Inexcusable service

So we went to KFC Observatory at about 17:35, we placed an order for an 8 piece family treat which comes with 3 sides, we chose 2 x 4 wings and 1 pair of snack burgers and then ordered 2 x mini loaves and a regular gravy then reconfirmed the order with the lady at the drive-thru, then made payment and proceeded to the next window, at the pick up window we received our wrong order, they gave us 4 snack burgers and 1 x 4 wings and then the guy with the dreads then apparently sorted it out,We got home and there was only 1 x 4 wings, 1 mini loaf, the gravy and the chicken, we then raced back to KFC but we forgot the slip at home, we asked the guy at the pick up window to please fix the order (for the second time now) and explained the situation and he told us that he did infact place all the food in the bag, which we advised that we would not have driven all the way back from Woodstock if the order was correct. He then advised that he has to check camera footage even though he knew that we were there like 15 minutes ago. We then had to explain ourselves to the manager, I informed the manager that they could check my phone that I paid with my card and add up everything which amounted to R218.60. They eventually sorted out our order but we ended up with cold food due to the inconvenience. The slip does not show a breakdown of the family to treat meal with its sides. It just shows Family treat meal and the extras we ordered. I understand mistakes but do not tell us we are lying when you know you only removed the incorrect items and did not place all our food in the bag. The slips show 2 x mini loaves yet we received one. Surely you should take more care in your customer service?? Food was tasteless, the experience was dismal and currently, our experience at a branch we always visit is hanging by a thread.